Kamo’oalewa, “the Third Moon,” or more accurately, a “mini-Moon” of Earth, may have originated from the massive Giordano Bruno impact crater.
Using numerical simulations, a team led by astronomer Yifei Jiao from Tsinghua University in China has identified the “homeland” of Kamo’oalewa: the Giordano Bruno impact crater on the Moon.
Previously, Kamo’oalewa, an asteroid that unexpectedly appeared in 2016, puzzled scientists.
Giordano Bruno crater on the dark side of the Moon, the hemisphere not facing Earth – (Photo: NASA)
This asteroid does not orbit Earth in the same manner as the only official natural satellite, the Moon. Instead, it completes an orbit around the Sun in 366 days, nearly coinciding with Earth’s rotation period.
This gives it the appearance of orbiting Earth, leading to its classification as a “mini-Moon” of our planet.
Referred to as “the Third Moon” because prior to it, an asteroid named 2023 FW13 was also discovered to have quietly orbited Earth for thousands of years and will only depart in about another 3,700 years, earning the nickname “the Second Moon“.
At the end of 2023, a research team from the University of Arizona (USA) demonstrated that the composition of Kamo’oalewa is similar to that of the Moon, suggesting it could be a fragment of the Moon that broke off during the impact.
The new research by Dr. Jiao and colleagues further supports this hypothesis by modeling the impact to infer the type of collision necessary, the size of the crater left on the Moon, and other related factors.
All models pointed toward Giordano Bruno.
This impact crater has a diameter of 22 km and is less than 10 million years old, aligning with the University of Arizona’s estimate that Kamo’oalewa is only a few million years old.
“It is clear that the largest, youngest craters are more likely sources, as they produce more debris that remains in space. Giordano Bruno is the only crater that meets this criterion,” the authors from Tsinghua University wrote.
The pyroxene composition around the walls and rim of the crater is similar to that of Kamo’oalewa.
It is estimated that up to 400 fragments the size of Kamo’oalewa could be ejected from the site due to the impact of an asteroid with a diameter of just 1.66 km.
Most of these fragments will be ejected from the Earth vicinity or co-orbital with Earth within about 10 million years, although exceptions are possible. Kamo’oalewa is one such exception.
More conclusive evidence is still needed to confirm this, but humanity has a great opportunity: There are undoubtedly still some lunar meteorites related to Giordano Bruno scattered on Earth.
